A powerful lawmaker renewed a call Tuesday for a two-year budget deal that avoids a government shutdown and sequestration, expressing specific concerns about the Pentagon budget.

“We don’t want another shutdown. We don’t want another slowdown,” said Sen. Barbara Mikulski, D-Md., the Senate Appropriations Committee chairwoman who oversees discretionary spending for all federal agencies. She warned, specifically, of the possibility of furloughing 650,000 national security employees early in 2014.

“This is unacceptable,” Mikulski said. “You cannot protect a country and run a government like that.”

Military leaders already have warned that readiness has been degraded by current budget cuts, she said, and things could get worse.

“This is a dangerous time in the world, with numerous threats to our security,” she said. “We cannot operate our military on the cheap.”

Her remarks come as the House and Senate are engaged in spending and debt reduction negotiations aimed at having an agreement by mid-December, in time to write funding bills to keep the federal government operating beyond Jan. 15, when temporary funding expires. There already has been a 17-day partial government shutdown as Congress has passed none of the 13 bills needed to keep various parts of the government running.

“We need to have this agreement and we need to have it sooner rather than later,” Mikulski said, warning Congress expects to be in session only eight days between the Dec. 15 deadline for the budget agreement to be reached and the Jan. 15 deadline for when another government shutdown is possible.

She encouraged budget negotiators to try to reach a deal before Thanksgiving to give more time to work out details of 2014 spending bills. “We need to be able to step up to the place and not only avoid a crisis like a shutdown. We also have to avoid the crisis of confidence that is occurring in our government.”

Mikulski said what she and Rep. Hal Rogers, R-Ky., the House Appropriations Committee chairman, are “really worried about is that if we don’t act, sequester kicks in Jan. 15.” That could require a $109 billion cut in federal spending including a $54 billion to 57 billion reduction for the military. “What an awful way to do business in our government.